Process of dehydrating colloid material



Sept. 1, 1936;

'M: VAN ROGGEN ET AL -PROCESS OF D EHYDRATING COLLOID MATERIAL Filed Feb. 16, 1933 Patented Sept. 1, 1936 mm STATES.

PATENT orrics 2.03am rnocsss or mtnrnna'rma contain Mathieu van Roggen, Sprimont, and Leo Robin,

- Brussels, Belgium Application February is, 1933, Serial No 1,144

In France February 18 1932 BClaims. ((1100-37) The dehydration of colloid materials, e. g. peat,

is attended by considerable practical dificulties due to the fact that'water is retained-in saidmateriais in such close association therewith that it 6 cannot beexpelled therefrom by mere pressure.

It is known, moreover,- that the dehydration of such materials by pressure becomes possible it they 'can be divided into iragmenta'and such fragments be suitably sprinkled with a dry pm- 10 verulent material. In the case of raw peat, the

dry pulverulent material thus added generally consists of powdered peat.

. However, the practical application or the aforesaid dehydrating processsuflers from vdisadvanf l tages' usually arising'from a lackoi consistency in the material to be treated preventing ,such

material from being divided positively, from d1!- ficulties in coating pieces of muddy consistency with a dry powder, and from the natural tendency 20 displayed by said materials of muddy consistency to amalgamate homogeneously with any dry pulverulent material added thereto. Furthermore, sincethe material to be treated frequently cont'ains an excess of tree liquid, the dry pulverulent 25 material becomes moistened by mere contact with the same and thus loses the greater part of its value. As a result, it becomes necessary to usedry pulverulent material in such large'quantities that the manipulation and drying ot the same 80 ieopardize'the commercial value of'the process.

"40 from the material undergoing treatment before they have become saturated with moisture, and they are only brought back intocontact with said material after having been sufllciently dried to be fitted for use as eillcient dehydrating agents 1 into and through a press together with the mate- 45 5 once more.

The permeable and absorptive bands used according to our invention may consist of any suitable flbrous textile material such as cotton, flax,

h mp, lute, wool, cocoa-fibre or the like, i. c. any

I 50 flbroustissue insoluble in the liquid to be expressed but adapted to be moistened thereby. It

has been found that the power 01' a colloid mate- 'riaitirretain liquid is'lessened when said material is placed in contact with aband o! the class 86 aforesaidthat .upon being subjected to pressure d is compressed in contact with one or more said material exudes a quantity or liquid considerably in excess oi that which the band is adapted'to absorb, and that'the' permeable and absorptive band has, to say, the power to initiate an abundant exudation of liquid. 5 The permeable and absorptive band or bands may be charged with materials, such as dry pulverulent peat for example, adaptedto lessen the power of the colloid materialto retain liquid, or with substances such as coagulants or electrolytes, adapted to promote the coagulation oi the colloid .-materia'l. It is likewise preferable to make use of a band or bands-whereof the material has been treated with a tanning agent such as a bichro mate, for example, since bands thus prepared promote coagulation of the material undergoing treatment and, are better adapted to withstand rotting. I

The use of permeable and absorptive bands.

according to our invention ofl'ers important ,ad-to vantages over that of noncohesive substances such as pulverulent peat or saline layers. Such bands are suitable for the treatment of colloid materials of any degree of consistency, the absorptive material of which they are constituted may be. separated positively from the material undergoing treatment after having become moistened, the absorptive power oi saidbelts may be iully renewed by appropriate drying, and said belts may likewise be used as conveyors to carry the colloid material into and through the press.

The use of permeable and absorptive belts according to. our invention may be combined with the usual process} involving the action oi puiver- -ulent material. Such a combinationol processes may, for example, take the form of removing a first quantity of liquid from the colloid material by means of one or more bands, and thereupon completing dehydration by means oi pulverulent dry material, or by the combined use ot a band 40 according to the invention and of pulverulent dry material.

The dehydrating installation according to our invention comprises essentially a band travelling rial to be treated, said band passing thereafter in contact with vscrapersadapted to detach said material therefrom after treatment thereof, and through a-drying device or chamber adapted to restore to said bandits absorptive power. Upon emerging from the drying device or chamber, the band is preferably caused to travel. through a cooling device or chamber, since the treatment is most eflective when applied cold, the material of the band being liable to absorb liquid too quickly, ,5

' upon belt 2 by means of a hopper feeding apif it is at a higher temperature tm the material undergoing treatment.- v

' If desired, an installation of the class described may conveniently be associated with devices adapted to divide the material to be treated-and to sprinkle the same.

Further details and features of our invention. will become apparent from the appended description taken in conjunction with the accompanying drawing, showing diagrammatically, by way two constructional embodiments,

- sponding devices 52, i3, and through cooling dc of example, V thereof. Insaid drawing: 7

Fig. 1 shows an installation wherein a separate set of bands or belts is used for each press,

Fig.2 illustrates an installation wherein one same set of belts or hands passes through both presses'in succession.

Like-reference numerals apply to similar membersin eachof the'figures.

Fig. 1 illustrates a plant comprising an endless belt 2, adapted to convey into and through a press d a relativelythin layer of material, e. g. peat. Belt-2 may be made of cotton, flax, hemp, jute, wool, cocoa-fibre or the like,'i..e. of any'fibrous material insoluble in the liquid to be expressed but adapted to become moistened thereby.

Ihe material to be treated is loaded directly paratus d, adapted to divide said material into small pieces. The feeding and dividing appara- 'tus dis located inthe line of travel of belt 2,

between two powder-sprinkling devices 5, 3 fit. ted in front of and behind said apparatus t, respectively. Upon entering the pressed, the peat is compressed. between belt 2 and a similarly constituted belt l whereby free liquid is readily expressed from the peat together with such further water asmaybe expelled under slight pressure.

- The water thus expelled passes through the per= meable belts t, I, together with that exuded in consequence of the reduction of the power of the treated material to retain liquid, resulting from contact with and pressure from said belts.

Belts 2 and i are preferably charged with sub= stances adapted per se to promote the coagula tion of peat or to reduce its retentive mwer rela tively to the liquid tobe'expressed. in particular, it is advantageous to make said belts of a tanned material, for example fibrous vegetable Belt 2 likewise passes in contact with a scraper vt, adapted to cause the material to drop onto a belt it. Belt 2' then travels through a container i 9 wherein it becomes charged with substances adapted to promote the coagulation of peat or to lessen the power of the same to retain water.

Container ll. may be filled with an electrolyte, for example. Y

Belt 2 then passes through a drying device or chamber it. It is desirable that the belt which receives the material to be treated be cold and to this end, belt 2 is caused to travel through a ccol== .ing device 22. Belt l is likewise caused to travel through a drying device it and through a cool- .ing device as, similar to devicesfiZ and it, respectively.

. The belt it, similar tobelt 2, is caused to travel.

together with the material loaded thereupon between crimping-rollers is adapted to shape said charged with dry powdered peat.

' aosiaeoe material into small bloom. Before the layer of material thus crimped or shaped into blocks enters a second press it, it may be strewn with dry powdered peat by means of a sprinkling device it.

. Whilst the material is in press it, it is subjected to scrapers 8, 9, respectively, through drying devices or chambers it, 26, similar to the correvices 2d, 25, similarto'the corresponding devices After travelling through the various devices above recited, the belts 2, l, it, and iii are led back into contact with-the material under treatment, inorder to act thereupon by virtue of their particular constitution and, where sprinkling devices are provided. because they have been In most cases the powder sprinkling devices sit-= nested in front of the first press may be. omitted, and sometimes those placed before the entrance to the second press may be omitted likewise. In

v such cases the material'is preferably fed directly into the presses, the feeding and dividing sppa= ratus a preceding the first press and the crimping rollers id, located in front of the entrance to the second press, being omitted. In some cases, a set of devices such as 4, 5 and 6 may be mounted in front of the entrance to the second press it.

Should the initial condition oi. the colloid ma terial besuitable, use may oi course be made of a'single press instead of several presses in succession. Fig. 2- illustrates an installation wherein belts- 2, 1! travel through the first press 3 and likewise through the second press it. The belts must be dried after emergingirom the first press and m -fore entering the second press. To this end, use

is made of drying devices or'chambers it, it,

' which may likewise be adapted to dry said belts between their issuefrom the second press and their re-el try into the first press.

In the constructional embodiments illustrated in Figs. 1 and 2, it is not of course essential that all the belts be absorptive oi the liquid to be expressed during the period of compressing. For example, the belts l and ll may be constituted in this manner whilst other belts, such as 2 and is, may he made of indie. rubber or the like, is act merely as impermeable conveyors. In this case, the impermeable belts such as 2 and it neednot travel through drying devices or chambers. It is likewise clear that all the belts such as 2,

i, it, and ii, made 01' a material absorptive oi the liquid to be expressed during the period of compression, may be charged with. a substance adapted to promote the coagulation oithe material undergoing treatment or to reduce its power to retain the liquid to be expelled.

our invention is not limited to the constructional embodiments herein illustrated by way of exam pie, and various modifications may be made in the shape, arrangement and constitution of the various members, without departure from its principle and scope as defined by the appended claims.

We claim:

1. In a.prccess of dehydrating colloid mate rial, continuously bringing crude colloid material into cdntact with an endless band adapted to ab-' sorbmoisture, continuously moving said band with the material in contact therewith, applying pres. '75

lid

aoeaeoe sure to said band to initiate the exudation of liquid from the material in contact therewith, increasing said pressure to cause liquid to be exhausted from the colloid material at a higher rate than it can be absorbed by the absorptive band, releasing the pressure before said band is fully moistened, separating said band from the colloid material, drying said band, cooling the dried band to about'the temperature of the crude colloid material, and repeating the aforesaid operations in cyclic sequence each time with a fresh charge of crude colloid material.

2. In a process of dehydrating colloid material, feeding crude colloid material onto a pervious endless belt adapted to absorb moisture, continuously moving said belt, applying pressure to said belt to initiate the exudation of liquid from the colloid material in contact therewith, gradually increasing the pressure against the colloid ma-' terial on said belt to cause liquid to be expelled from the colloid material through said belt at a considerably higher rate than it can be absorbed by the absorptive belt, releasing the pressure before said belt is fully moistened, separating said belt from the colloid material, drying said belt by heating, cooling the dried belt to about the temperature of the crude material to be treated and'repeating the aforesaid operations in cyclic sequence each time with a fresh charge of crude colloid material.

3. In a process of dehydrating colloid material, feeding crude colloid material onto a pervious endless belt adapted to absorb moisture, adding an absorbent powder to the colloid material on said band, applying pressure to said belt to initiate the exudation of liquid from the colloid material in contact with said powder and with said belt, gradually increasing the pressure against said colloid material to cause liquid to be expelled from the colloid material through said belt ata considerably higherrate than it can be absorbed by said belt and by said powder, re-' leasing the pressure before said belt is fully moistened, separating said belt from the material thereon, drying said belt by heating, cooling the dried belt to about the. temperature of the crude material to be treated, and repeating the aforesaid operations in cyclic sequence each time with a fresh charge of colloid material.

4. In a process of dehydrating colloid material, feeding crude colloid material onto a pervious endless belt of tanned fibrous material adapted cause liquid to be expelled from the colloid material through said belt at a considerably higher rate than it can be absorbed by theasorptlve belt, releasing the pressure before said belt is fully moistened, separating said belt from the colloid material, charging said belt with a material having a coagulating effect on colloids, drying said belt and then cooling it to about the temperature of the crude material to be treated and repeating the aforesaid operations in cyclic sequence each time with a fresh charge of crude colloid material.

5. In a process of dehydrating colloid material, feeding crude colloid material onto an endless band adapted to absorb ,moisture, continuously moving said band, applying pressure to said band to initiate the exudation of liquid from the colloid material in contact therewith, increasing the pressure against said colloid material on said band to cause liquid to be expelled from the colloid material at a higher rate than it can be absorbed by the absorptive band, releasing the pressure before said band is fully moistened, separating said band from the colloid material by scraping, drying said band by heating, cooling the dried bandto about the temperature of said material, and repeating the aforesaid operations in cyclic sequence each time with a fresh charge of colloid crude material.

6. In a process of dehydrating colloid material,

continuously bringing crude colloid material into contact with a band adapted to absorb moisture, continuously moving said band with the material in contact therewith, applying pressure to said colloid material.

MATHIEU VAN ROGGEN. LEO ROBIN. 

